초록 ▼

A system and method for positioning an electronically scanned, phased array antenna disposed on a moving platform, such as an aircraft, to enable the antenna to remain pointed at, and track, a geostationary satellite as the moving platform is in motion. The antenna is mounted on a support which is c

A system and method for positioning an electronically scanned, phased array antenna disposed on a moving platform, such as an aircraft, to enable the antenna to remain pointed at, and track, a geostationary satellite as the moving platform is in motion. The antenna is mounted on a support which is coupled to an output shaft of a motor. The motor is used to rotate the support, and therefore the antenna, as needed to maintain the beam of the antenna directed at the satellite. The support is rotated only after a scan angle of the beam of the antenna exceeds a predetermined maximum scan angle. The degree of rotational movement of the support is further selected to be such that only a minimum number of adjustments to the position of the support are needed to maintain the scan angle of the beam of the antenna within the desired maximum scan angle over a large distance of travel of the aircraft. The invention significantly reduces the frequency of adjustment of the position of the support required to maintain the antenna directed at the desired satellite, and thus significantly reduces wear and tear on the motor without adversely affecting the antenna's ability to track a target satellite.

대표청구항 ▼

1. A method for positioning an electronically scanned phased array antenna disposed on a rotatable support in real time, wherein the support is disposed on a moving platform, as said antenna tracks a radio frequency transponder fixed in position relative to the Earth, to maintain an actual scan angl

1. A method for positioning an electronically scanned phased array antenna disposed on a rotatable support in real time, wherein the support is disposed on a moving platform, as said antenna tracks a radio frequency transponder fixed in position relative to the Earth, to maintain an actual scan angle of a beam of said antenna within a predetermined scan angle range necessary to maintain a desired bandwidth of said antenna at a given wavelength, said method comprising the steps of:determining a maximum scan angle not to be exceeded in order to maintain said desired bandwidth when said antenna is being scanned to track said transponder while said support is being held stationary; defining a rotational path of movement of said antenna to include a plurality of generally evenly spaced apart locations to which said support can be rotated, with a distance between adjacent ones of said locations being determined so as to result in a change in magnitude of less than about twice that of said predetermined maximum scan angle; monitoring said actual scan angle of said antenna during movement of said moving platform and, if said actual scan angle exceeds said predetermined maximum scan angle, rotating said support to a next adjacent one of said locations and in a direction necessary to point said antenna relative to said transponder to cause said actual scan angle to be reduced in magnitude below said maximum scan angle.